Liquid tank



FIG. 1 is a top, front isometric view of a liquid tank showing our new design;

FIG. 2 is a bottom, rear isometric view thereof;

FIG. 3 is a top view thereof;

FIG. 4 is a front view thereof; and,

FIG. 5 is a side view thereof. 

CLAIM The ornamental design for liquid tank, as shown. 